I. Field of the Invention
The present invention relates to an adjustable centering tool for use in pipes of varying inner diameter.
II. Description of the Related Art
A centering tool is connected to various equipment and tools during work and measurement operations being carried out in an oil or gas well. Also, a verification of the inner diameter of the well is made using a centering tool, as well as of the existence/non-existence of obstructions in the wellbore.
Today, various centering tools are used for such tasks, each being adapted to the inner diameter of each well, and the contractor must hence know in advance the range of well diameters that are to be inspected and carry the appropriate tools for each of the dimensions in question.
U.S. Pat. No. 2,427,052 discloses a scraper tool in which a set of wings is forced outwards by pistons. The pistons and the wings have cooperative, sloped surfaces. By increasing the fluid pressure through the tool string the pistons are pressed against each other, forcing the wings outwards. A spring pulls the wings back to the starting position when the pressure on the pistons is removed.
U.S. Pat. No. 3,545,825 discloses a centering device for a drill string, the protruding wings of which may be adjusted and secured in position by screws.
U.S. Pat. No. 6,494,272 shows another example of wings that are forced outwards by supplying an additional fluid pressure.